Chuck(G)
25k Member
The one and same, with perhaps the exception of 3740 first track label records using DDMs (control marks).
Thank youThe one and same, with perhaps the exception of 3740 first track label records using DDMs (control marks).
I think the real reason is that initially, not all systems could be assumed to be able to LL-format floppies. Some required pre-formatted ones from the factory.By the way, the original CP/M was FM disks and used the worst-case data pattern of hex E5 for the blank sector data, and thusly the "erased" directory entry value. Later when machines started using double density, CP/M still had to use E5 even though it was no longer the worst case data formatting pattern. I seem to recall a two-byte pattern that was the MFM worst case. Chuck will know off the top of his head.
Welcome to the fun world of CP/M and 8bit computing. It is a great testament to CP/M's design elegance, portability and simplicity that new comers and preservation groups are discovering CP/M a new, even after almost 50 years, and find it worth learning. The late Dr. Kildall began developing CP/M in 1973 and the first pre-release 1.2 as custom DOS for Tordoe's S100 FDC in 1975. Yet, here we are in 2024 and hopefully for many more decades, will continue to enjoy CP/M.Some people (like me) are still discovering CP/M nowdays
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By the way, the computer history preservation association I'm member ...